Polyvinyl acetal resin composition



Patented Nov. 4, 1952 STATES PATENT" OFFICE No Dravving. Application J'une 3t 1950;

I Sl'ifll N 166,067

( Ole 260-313) 'my application. Serial No; 8282 filed February-13,,

1948 forxPlastic" Compositions. that application I; have. describeda'ryla. esters of: higher aliphatioacid's such as phenylioleatefor use'in polyvinyl; chloride resins. I. findi advantages in the use of;plasticizers of: the kind described in" the said copendingc application;with the: polyvinyl acetal. resins, in makingplasticsr suitable for useas the laminating agentin safety glass. manufacture;

The plastic." which. isconventionally used. in making safety glass ischiefly polyvinyl butyral. Thisr polyvinyl butyral is ordinarilyplasticized with. dibutyl sebacate, triethyleneglycol dihexoate',dibutyl cellosolve; adipate-,.- or the 1ik.a

My new plasticizer; which consists: verylargely of a higher fatty acid,is much lessrexpensive: per pound. than the plasticizers; referredsi to;above. Inladdition, my plasticizerlengthens thewrange of: temperature inwhich the: pl'asticizedi polyvinyl butyral. is of the. properconsistency-for use as the? laminating plastictinsafety glassi.

There has been? heretofore: the problem: of

making a: plastic which: would: betneithen too" soft atelevatedtemperaturea to: which: azwiirzlshield, for example, may be:exposed, nor' so rigid. onhard as to permit delamination of thesafetyglass when subjected to sharp. iinpact at the lowest wintertemperatures. I consider that the explanation of the widerange"of'temperatures, under which. the polyvinyl acetal' plas-ticscontaining my new plasticizer are satisfactory, is-ldue in part tosecondary valenceiorces. and thelong chain structure oftheplasticizer,favoring flexibility, in conjunction with the-'aryl group which promotescompatibilityb8tW6II-', the plasticizer and V purposes are formaldehyde,acetaldehyde, propionaldehyde, and glyoxal,

The polyvinyl acetal tobe used is either: one available commercially-or"made by the conventionali process, such as, partial hydrolysis. ofpolyvinyl acetate. f ormat'e, "or. propionate and. combination ofjth'ehydrolysis product, namely, the polyvinyl alcoholl with. the. selectedaldehyde. Thereisno advantage musing the iormate, propionate, andchloracetate over thepolyv-inyl acetate as. the raw. material to. be.hydrolyzed to supply the polyvinyl alcohol. to combine with theselectedaldehyde. For that reason the polyvinyl acetate is. preferred.as the. rawma eriaL.

' Examples of the plasticizer that may be used are esters ofamonohyd'ric. phenol. with monocarboxylic higher fatty acids containingat least 16- carbon. atoms to the molecule and of monocarboxyliccycloaliphaticl acids; Examples of such esters are phenyl oleate,phenylabietate, phenyl esters of the acids oftall oil and thecorresponding unsaturated acid esters of alkyl phenolssuch as m"-- andp-cresol and tertiarybutyl phenol. Such alkyl phenols maybe generallyclassed asalkyl phenols containing not more than l' 'carbon atoms in thealkyl group.

As to proportions, thepla's icizeris used in amount varying with theextentof pla ticization desired, as in theratio of5to'-1ll0' partsby'weight for" 100" of polyvinyl butyral or like polyvinyl acetal'resin. Formost' commercialpurposes, I'use -25 to" 75 parts of thepl'astici'zer, to produce a finished product" that is of properconsistency over the range of temperatures to which it is exposed duringoutdoor-use;

'Ih'einvention willbe' furtherillus rated by description in connectionwiththeiollbwingi specificexampl'esoi the practice ofi't.

Ewample l.

The resin used was typicalbi 'a class which had found widservice in" theproduction of plastic interlayers forsafety glass; and consistedessentiall-yofa thermoplastic material which may be described as"polyvinyl butyral" such as might be produced for'examp'le by-thepartiaf'hydrolysis of polyvinyl acetate and subsequentcondensationorfronrfi to flmolsof' witlrl moFof normal butyraldehyde. 100 parts ofthis resin, polyvinyl butyral, was blended thoroughly with parts ofphenyl oleate and extruded in the form of a thin sheet .025 inch inthickness. This was made up into a laminated composition by applying theresin sheet between two clean pieces of plate glass and the wholepressed lightly first for the removal of air and the creation of atemporary bond and finally cemented under a pressure of pounds persquare inch at 225 F. under liquid pressure in an autoclave for thirtyminutes. The composition was cooled under pressure, removed and washed.The resulting safety glass composition showed extremely high resistanceto shattering both at F. and 120 F.

Example 2 The procedurev of .Example .1 was followed using p-cresyloleate instead of phenyl oleate and the product was eminently suited foruse as a glazing material in automobiles.

Example 3 The precedure of Examples 1, 2 and 3 above were followedexcept that the polyvinyl butyral resin was substituted on a pound forpound basis by each of, the other polyvinyl resins listed above, withthe production of plastics of good properties and proper consistency foruse as a safety glass laminating material over a wide range oftemperatures.

With the different polyvinyl acetal resins the proportion of theplasticizer used was varied withinthe range of 25 parts to '75 parts for100 parts of the polyvinyl acetal resin. Within this range theproportion of plasticizer is made larger the smaller the number ofcarbon atoms in the aldehyde which is reacted with the polyvinylalcohol.

Example 5 Ten parts of the polyvinyl butyral resin were dissolved in 90parts by weight of a 9:1 blend of ethyl alcohol to ethyl lactate. To 100parts of this solution there were added 4 parts of parachloro phenyloleate. This produced a clear solution. The solution was poured onamalgamated tin plates and the solvent allowed to evaporate. Theresulting dry film was placed between glass plates and consolidatingpressure was applied; The'assembly was then heated in an oven for onehour at 85 C. and then cooled to room temperature before the pressurewas re leased. The resulting sandwich or safety glass showed greatresistance to shattering over a wide range of temperatures.

The aryl esters described herein may be blended with each other or'withother plasticizers that are soluble in the aryl esters, for use as aplasticizer mixture. Thus phenyl oleate may be mixed with dibutylsebacate, dibutyl phthalate, dioctyl phthalate and dibutoxyethyladipate. Suitable proportions are 25 to 75 parts of any one of theplasticizers to 100 parts of the total weight of plasticizer mixture.

For convenience in identification, the polyvinyl acetals made with thealdehydes listed 4 above are named, in order, polyvinyl formal,polyvinyl acetal, and polyvinyl propional. They and also the polyvinylbutyral may be used alone or mixed with each other along with myimproved plasticizer.

It will be understood also that it is intended to cover all changes andmodifications of the examples of the invention herein chosen for thepurpose of illustration which do not constitute departures from thespirit and scope of the invention.

What I claim is:

1. A plastic composition comprising a polyvinyl acetal resin and phenyloleate, the phenyl oleate serving as plasticizer for the resin.

2. A plastic composition comprising a polyvinyl acetal resin and thephenyl ester of an unsaturated fatty acid containing at least 16 carbonatoms to the molecule, the ester serving as plasticizer for the resinand the proportion of the ester being 25 to parts by weight for parts ofthe resin.

3. A plastic composition characterized by consistency suitable for theplastic laminating material of safety glass over a Wide range of outdoortemperatures, the composition comprising a polyvinyl acetal resin and anester of an unsaturated fatty acid containing at least 16 carbon atomsto the molecule with a phenol selected from the group consisting ofphenol and alkyl phenols having not more than 4 carbon atoms in thealkyl group, the ester serving as plasticizer for the resin.

4. A plastic composition comprising polyvinyl butyral resin and an esterof an unsaturated fatty acid containing at least 16 carbon atoms to themolecule with a phenol selected from the group consisting of phenol andalkyl phenols having not more than 4 carbon atoms in the alkyl group,the ester serving as plasticizer for the said resin.

5. A plastic composition comprising polyvinyl butyral resin and an esterof an unsaturated fatty acid containing at least 16 carbon atoms to themolecule with a phenol selected from the group consisting of phenol andalkyl phenols having not more than 4 carbon atoms in the alkyl group,the ester serving as plasticizer for the resin and the proportion of theester being 25 to 75 parts by weight for 100 parts of the resin.

' MAXWELL A. POLLACK.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS

3. A PLASTIC COMPOSITIN CHARACTERIZED BY CONSISTENCY SUITABLE FOR THEPLASTIC LAMINATING MATERIAL OF SAFETY GLASS OVER A WIDE RANGE OF OUTDOORTEMPERATURES, THE COMPOSITION COMPRISING A POLYVINYL ACETAL RESIN AND ANESTER OF AN UNSATURATED FATTY ACID CONTAINING AT LEAST 16 CARBON ATOMSTO THE MOLECULE WITH A PHENOL SELECTED FROM THE GROUP CONSISTING OFPHENOL AND ALKYL PHENOLS HAVING NOT MORE THAN 4 CARBON ATOMS IN THEALKYL GROUP, THE ESTER SERVING AS PLASTICIZER FOR THE RESIN.